Styrene is an important monomer used in the manufacture of many polymers. Styrene is commonly produced by forming ethylbenzene, which is then dehydrogenated to produce styrene. Ethylbenzene is typically formed by one or more aromatic conversion processes involving the alkylation of benzene.
Aromatic conversion processes, which are generally carried out utilizing a molecular sieve type catalyst, are well known in the chemical processing industry. Such aromatic conversion processes include the alkylation of aromatic compounds such as benzene with ethylene to produce alkyl aromatics, such as ethylbenzene. Other alkylation processes include the alkylation of toluene with methanol and/or formaldehyde to produce styrene and ethylbenzene. Unfortunately, these alkylation processes have generally been characterized by low yields of desired products and low selectivity to styrene and ethylbenzene.
The molecular sieve catalysts that are suitable for use in these alkylation reactions typically include zeolites. The most commercially available zeolites are prepared such that the zeolite crystal is greater than 1 μm.
In view of the above, it would be desirable to develop processes of forming styrene and/or ethylbenzene capable of increased yields and improved selectivity.